1. Field of the Invention
The present invention relates to folding camping trailers and, more particularly, to folding camping trailers having expandable beds.
2. Description of the Prior Art
Folding camping trailers typically have a trailer body with an extendable hard-shell top portion. The trailer body usually includes two expandable beds that extend slidably outward from end walls of the trailer body. An example of a folding camping trailer having a pair of expandable beds is disclosed in U.S. Pat. No. 4,825,235 to Zwick.
Prior to the use of expandable beds in folding camping trailers, the sleeping area of the beds in folding camping trailers was generally constrained by the area defined by the trailer body. For example, a trailer body 8 feet long by 5 feet wide has a total "living" area of 40 square feet without expandable beds. Therefore, if a prior art trailer body without expandable beds was equipped with two equally sized beds, each bed could be no larger than 4 feet long and 5 feet wide for a total usable sleeping area of 40 square feet.
To provide a usable sleeping area that is larger than the living area defined by the trailer body, the Zwick patent generally discloses a pair of expandable beds which extend outward from the end walls of the trailer body. The expandable beds disclosed by the Zwick patent each generally include a pair of parallel extension arms, a first mattress frame attached to the parallel extension arms and a second mattress frame coupled to the first mattress frame. A rear mattress portion is supported on the first mattress frame and a front mattress portion is supported on the second mattress frame. The second mattress frame is pivotally connected to the first mattress frame by parallel pivot links, with the second mattress frame resting on an upper surface of the rear mattress portion during periods of nonuse. The parallel pivot links are connected by a torsion bar.
In operation, the expandable beds disclosed by the Zwick patent are extended slidably away from the end walls of the trailer body. The first mattress frame at each end of the trailer body does not rest on the trailer body but extends beyond the trailer body a distance approximately equal to the width of the second mattress frame. When each expandable bed is pulled out to its full extent, or to its extended position, the second mattress frame for each expandable bed is pivotally moved toward the respective end walls of the trailer body. The second mattress frame at each end of the trailer body rests on the parallel extension arms connected to the respective first mattress frames. The second mattress frame at each end of the trailer body fills in the space between the respective first mattress frames and the trailer body. The second mattress frame in combination with the first mattress frame at each end of the trailer body create two flat sleeping surfaces that together have a total usable sleeping area which is larger than the living area defined by the trailer body.
One disadvantage of the arrangement disclosed by the Zwick patent is that stacking the second mattress frame on top of the first mattress frame when the trailer is in the folded position increases the overall height of the folding camping trailer and, in particular, the top portion. In order to keep the overall height of folding camping trailers standardized, folding camping trailers with stacked beds necessarily suffer a corresponding decrease in the trailer body height to compensate for the additional height of the top portion. Therefore, two different trailer bodies must be manufactured along with two different top portions in order for the overall height of folding camping trailers with expandable beds to be equal to the overall height of folding camping trailers without expandable beds.
It is, therefore, an object of the present invention to provide a folding camping trailer with expandable beds which do not increase the overall height of the folding camping trailer and which overcomes the disadvantages present in the prior art.